Compensated action nonreturn exhalation valve,more particularly for respiratory mask



May 20, 1969 E. P. v. R. GODEL 4, 7

COMPENSATED ACTION NON-RETURN EXHALATION VALVE, MORE PARTICULARLY FORRESPIRATORY MASK Original Filed March 19. 1962 m VEN TOR {ZOO/9X0 PAUL l/cfo/P/fflauz 6006A BYQM ATTORNEY I United States Patent 3,444,857COMPENSATED ACTION NONRETURN EXHALA- TION VALVE, MORE PARTICULARLY FORRESPIRATORY MASK Edouard Paul Victor Raoul Godel, 16 Rue du Champ-Renie, Saint-Maur, Val-de-Marne, France Original application Mar. 19,1962, Ser. No. 180,741, now Patent No. 3,228,409, dated Jan. 11, 1966.Divided and this application Oct. 11, 1965, Ser. No. 494,709

Int. Cl. A62b 7/02, 23/06 U.S. Cl. 128-142 4 Claims ABSTRACT OF THEDISCLOSURE Exhalation valve associated with a respiratory maskcomprising a bellows supplied with a gas at a pressure corresponding tothe respiratory pressure, a spring placed in series with said bellows atthe exterior thereof and a flat valve urged together by said spring andsaid bellows against a seat to close an opening through which exhaledair escapes to atmosphere.

This application is a division of parent application Ser. No. 180,741,filed Mar. 19, 1962, now Patent 3,228,409.

The present invention relates to an exhalation nonreturn valve, moreparticularly for equipping respiratory masks.

Masks, applying a non-return valve of the present type, whose simpledesign leads to the making of an inexpensive article and whose workingis dependable, can be used for providing oxygen at over-pressure toaeroplane pilots, in order to neutralize the effect of the rarefactionof the air at high altitudes and may also be used for insufilatingcertain patients under air or mixed gaseous pressure in order to ensurethe ventilating of their lungs. Another application of a non-returncompensated valve in accordance with the present invention is forregulating a circuit conveying a gaseous fluid.

An important advantage of the invention lies in the fact that the valvecan be used also without compensation, i.e., for supplying a gaseousmixture at the ambient air pressure and opposing any entry of air thatmight run the risk of denaturing the latter.

In a known device of that type, a valve has been proposed having apneumatic distortable chamber, the top portion of which is delimited byan annular distortable fold constituting a diaphragm and surrounding anopen casing in which is disposed a spring to urge a plate against aseat, said plate being guided in said cover by an annular flange. Inthis known structure, the pneumatic chamber also contains a springurging said diaphragm toward said cover and hence toward said plate andfurther gas pressure is applied into the pneumatic chamber. It has beenobserved that the known structure presents drawbacks. Particularly theexhalation pressure must overcome the pressure exerted both by the twosprings and the gas pressure in the pneumatic chamber, gas pressurewhich is at least equal to the pressure in the breath of the user.Further, particularly when the exhalation valve is used in airplanebreathing equipments there are important risks of ice formation betweenthe cover and the annular flange guiding the plate urged against theseat. To eliminate in part the above risks, the known valve is generallyprovided with heating means but such heating means cannot preventoxidation between said cover and annular flange oxidation due to thefact that the exhausted air is necessarily wet and since the surface incontact of said cover and annular flange is important; such an oxidationmay rapidly cause blocking of the flange and plate.

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The invention creates a new structure whereby any risk of blocking iseliminated and in which further heating means are also eliminated.

According to the invention, the non-return valve, more particularly fora respiratory mask, comprises a perforated casing, communicating withthe exterior and capped by a cover also perforated emerging in the mask,such cover being provided with an annular seating cooperating with aclosing axially guided plate with which a pneumatic chamber is connectedby a calibrated spring interposed between said plate forming valve andsaid pneumatic chamber constituted by an axially distortable bellowshaving means preventing radial distortion, axial guiding of said platebeing caused by substantially needle shaped members.

Various other characteristics of the invention will moreover be revealedby the detailed description which follows.

An embodiment providing the objects of the invention is shown by way ofa non-restrictive in the attached drawings,

FIG. 1 is a longitudinal section of a first form of embodiment of thevalve forming the object of the invention.

FIG. 2 is a view from above taken along the line II-II of FIG. 1.

FIG. 3 is an elevation, partly in section and on a smaller scale, of oneof the elements of this first form.

The valve comprises a cylindrical casing 1 having an annular collar 2projecting radially and a threaded cap 3 extending axially beyond thecollar 2 for screwing on a cover 4. The casing 1 and cover 4 areperforated so that their internal space respectively communicates withthe ambient air as shown and with a respiratory mask or other componenton which this unit is fixed adjacent the small collar 2. To this end,the casing 1 delimits lateral window 5 and the cover 4 is provided witha circular central opening 6.

A seating 7 of flexible material such as synthetic rubber or otherplastic material, is prolonged by an annular lip S, with a U-shapedprofile, surrounding a washer 9 inserted between the cover 4 and a cup10 bearing on the threaded cap 3 of the casing. This seating, thusmaintained, cooperates with a plate 11 constituting a flat valve forisolating or putting into communication two cavities 12 and 13 emerging,by the means described, in the ambient air and in the mask. The plate 11is integral with two coaxial substantially needle shaped guides 14 and15, the former sliding in a sheath 16, connected to the cover 4 by arms17 extending across the opening 6, and the latter sliding in a plug 18.The plug 18 has a disc-like shaped upper portion and a boss 19projecting downwardly and a stem 20 extending in a pipe 21 integral witha base 22 bearing against the bottom 23 of the casing 1. Extendingtoward the boss 19 of the plug 18 from the base 22 is a threaded tubularportion 24 which traverses an orifice 25 in the casing 1.

The boss 19 is surrounded by a sleeve 26 projecting inside a pleatedtubular bellows 27 the upper end 28 of which has an annular flange 29applied under the disc-like shaped upper portion of the plug 18. Thelower portion 30 of the bellows 27 is held between a small collar of anut 31, screwed on to the threaded tubular portion 24, and a cup 32,washers 33 forming spacers being inserted between the bottom 23 and thecup 32.

Rings 34 are placed around the ,bellows 27, in folds thereof, so as toprevent radial distortion of this bellows which may be advantageouslymade of thin synthetic material or rubber. The pipe 21 i branched, by aconnection 35, on to a gas supply line controlled by an independentpressure regulator (not shown) this supply line being essentiallyintended to supply the respiratory mask through a duct as shown. Hence,the bellows 27 forms a pneumatic chamber put under internal pressureequal to the supply line pressure, This internal pressure may be apressure called compensation intended to allow respiration at a pressureexceeding the pressure of the ambient air.

Moreover, the fact of the presence of the rings 34, enables the bellowsto transform the compensation pressure almost entirely into axialthrust.

Furthermore, a calibrated spring 36 is housed partially in the boss 19,to be interposed between the plate 11 and the plug 18, i.e. between theflat valve constituted by said plate and the bellows.

This non-return valve operates as follows: during an inspiration of theperson wearing the mask, the pressures prevailing in the cavity 13 andin the chamber within the bellows 27 are appreciably the same, andapproximately equal, at the exception of drop losses in the circuits, ata supply pressure exceeding the ambient pressure when there iscompensation.

The effective section of the face 28 of the bellows, on which thecompensation pressure provided for its exerted, is greater than thepassage section of the seating 7, in which the breathing out pressure ofthe person must be set up, so that the bellows 27 provides adifferential force F tending to press the fiat-valve 11 against theseating. During an inspiration, the mask is thus sealed.

When breathing out, the wearer of the mask must reject the gaseousmixture previously breathed in at a pressure slightly greater than thecompensation presusre, for he must overcome the force F, by thisdifference in pressure. The fiat valve 11 is released from its seating 7freeing an annular passage Opening through which the gaseous mixturebreathed out escapes through the cavity 13 towards the cavity 12communicating with the ambient air which is at lower pressure.

When the supply pressure is equal to the ambient pressure, thenon-return valve still works properly. Actually, it is the spring 36which exerts part of the force F on the fiat valve 11, because thepneumatic chamber within the bellows 27 can no longer be distorted, thepressure prevailing there being equal to the ambient pressure. Also, thespring 36 makes it possible to use the Valve whatever its position, forthe force that it exerts is greater than the Weight of the flat valve11.

Further spring 36 constitutes an emergency member because in case thepressure inside the bellows would accidentally drop it maintains thefiat valve 11 against its seat thus preventing the inside of the mask tobe put in communication with the atmosphere.

What is claimed is:

1. In an exhalation valve of the character described comprising a casinghaving apertures for communication with atmosphere, an open coverconnected to said casing and defining an aperture therebetween, saidcover providing for communication to the inside of a respiratory mask,valve seating means surrounding said aperture between said casing andsaid cover, a movable fiat-valve for closing said aperture between saidcasing and cover, a distortable diaphragm disposed inside said casing, agas supply line connected to said diaphragm and to the mask andsupplying gas substantially at the same pressure to the inside of saiddistortable diaphragm and to the inside of said mask, said distortablediaphragm urging said movable fiat-valve towards said seating means, andspring means also urging said fiat valve towards said seating means, theimprovement wherein said diaphragm comprises a bellows, the lowerportion thereof being connected to the bottom of said casing with saidsupply line opening also in said bottom of said casing to communicatewith the inside of said bellows, a plug closing said bellows at theupper part therefor, said plug having a central bore extending axiallyto said bellows, said fiat-valve having a substantially needle shapedcentral guide engaged in said central bore of said plug, said springbeing interposed between said plug and said fiat-valve to urge saidflat-valve towards said seating means, said seating means comprising alining made of flexible synthetic material, said cover further having acentral guide aperture and said fiat-valve having a second substantiallyneedle shaped guide extending upwardly and engaged in said cover wherebyaxial guiding of said bellows and of said flat-valve is ensured bycooperating action of said guides protruding on both sides of saidflat-valve.

2. An exhalation valve as set forth in claim 1 in which further saidplug closing said bellows has a downwardly extending stem containingsaid central bore, and said casing has a base having a downwardlyextending pipe extension connected to said supply line, said stem beingengaged in said pipe extension, said plug closing said bellows beingfurther recessed along its upper surface whereby said spring interposedbetween said plug and said fiat-valve is seated in said recess.

3. An automatically adjusted valve as set forth in claim 1 in whichfurther said bellows has a diameter slightly greater than the diameterof said seating means and in which further rigid rings are inserted inthe folds of said bellows whereby radial distortion thereof isprevented.

4. An automatically adjusted valve as set forth in claim 1, comprisingfurther annular ribs provided on both said casing and said cover andextending laterally therefrom for connection with said mask when saidcover is threaded on said casing.

References Cited UNITED STATES PATENTS 2,810,386 10/1957 Reed 128142.22,828,740 4/1958 Kindred 128142 2,966,917 1/1961 Bloom l37-5l2.2

WILLIAM E. KAMM, Primary Examiner.

US. Cl, X.R.

